Many of these genes are also known to act on body weight regulation or biological pathways related to fat metabolism. This large new study of more than 100,000 women from Europe, US and Australia highlights several specific genetic links between early puberty and body fat.

Puberty in women normally occurs between 11 – 14 years of age. If a child reaches a particular weight (around 45 kg), the onset of puberty is triggered. The heavier the child, the earlier puberty occurs, possibly affecting risk of later disease.

The study also found genes involved in hormone regulation, cell development and other mechanisms linked to age at menarche (the onset of menstrual periods in women), and this shows that puberty timing is controlled by a complex range of biological processes.

Massimo Mangino, author from the Twin Research Department at King's, says: 'It is fascinating how common genetic variants influence both early puberty and weight gain. The findings give us clues on how intricately linked are different biological processes.'

Professor Tim Spector, Director of Twins UK cohort said: 'This study shows the power of large genetic collaborations allowing us great insights into how puberty is triggered by precise amounts of body fat. Twin pairs are very similar for both puberty and body fat.'